10Base-T portable link tester

Abstract

A portable tester for local area networks comprising a AUI circuit coupled to a media specific transceiver, a battery, a push-to-test switch and four light emitting diodes and an RJ45 jack for each of a personal computer and a network hub. When the push-to-test switch is pushed, power is applied to the media access unit and a link pulse is generated for coupling via a PC jack to a personal computer plugged into that jack. The link pulse is also coupled to any network hub plugged into a hub jack. The PC and network hub cannot both be simultaneously connected. If whichever unit is connected receives the link pulse and generates its own link pulse which is received by the tester, a link status LED is lit green. Otherwise, it is left dark. If the unit connected outputs a data packet in response to receipt of the link pulse, a receive data LED is lit green. Otherwise, it is left dark. If the link pulse is positive-going on the correct line, a polarity LED is lit green. Otherwise, it is left dark.

What is claimed is: 
     
       1. A portable local area network testing device, comprising: a portable enclosure enclosing said testing device;   a first jack mounted on said portable enclosure for connecting a network hub to said testing device via a cable having transmit and receive pairs;   a second jack mounted on said portable enclosure for connecting a computing device to the testing device via a cable normally used to connect said computing device to said hub said cable having transmit and receive pairs;   a first display device mounted on said portable enclosure;   a second display device mounted on said portable enclosure;   a third display device mounted on said portable enclosure;   a fourth display device mounted on said portable enclosure;   a power supply mounted within said portable enclosure;   a switch mounted on said portable enclosure and coupled to said power supply and to said first display device, for selectively coupling said power supply to said first display device and to a switched power terminal, said first display device indicating when power from said power supply is available at said switched power terminal;   test means mounted within said portable enclosure coupled to said first and second jacks and to said first, second, third and fourth display devices and to said switched power terminal, for generating link pulses periodically and outputting said link pulses to each of said first and second jacks and any network hub coupled to said first jack and any computing device coupled to said second jack when said switch is moved to a state where said power supply is coupled to supply power to said test means, and for receiving link pulses from any network hub coupled to said first jack and for receiving link pulses generated by any computing device coupled to said second jack, and, if link pulses are received from said network hub, for driving said second display device to indicate link status as acceptable, and if link pulses are received from any said computing device coupled to said second jack, for driving said second display device to indicate link status as acceptable, and for receiving a data packet from any network hub coupled to said first jack in response to a link pulse generated by said testing device and transmitted to said network hub via said first jack, and, if a data packet is received from said network hub, for driving said third display device to indicate reception of a data packet, and for sensing correct or incorrect polarity of the transmit and receive pairs of conductors in any cable connecting a network hub to said first jack and, if polarity is correct, driving said fourth display device to indicate polarity is correct, and if polarity is incorrect, driving said fourth display device to indicate polarity is incorrect, and for sensing correct or incorrect polarity of the transmit and receive pairs of conductors in any cable connecting a computing device to said second jack, and, if polarity is correct, driving said fourth display device to indicate polarity is correct, and if polarity is incorrect, driving said fourth display device to indicate polarity is incorrect.   
     
     
       2. A network testing device, comprising: a portable enclosure enclosing said testing device;   a first jack mounted on said portable enclosure for connecting a network hub to said testing device via a cable having transmit and receive pairs;   a second jack mounted on said portable enclosure for connecting a computing device to the testing device via a cable normally used to connect said computing device to said hub said cable having transmit and receive pairs;   a first display device mounted on said portable enclosure;   a second display device mounted on said portable enclosure;   a third display device mounted on said portable enclosure;   a fourth display device mounted on said portable enclosure;   a power supply mounted within said portable enclosure;   a power supply;   a switch mounted on said portable enclosure and coupled to said power supply and to said first display device, for selectively coupling said power supply to said first display device and to a switched power terminal, said first display device indicating when power from said power supply is available at said switched power terminal;   a media access unit mounted within said portable enclosure and coupled to receive link pulses from devices coupled to said first and second jacks, said media access unit including circuitry to drive said second display device to indicate acceptable link status when there is a network hub coupled to said first jack which is transmitting link pulses to said testing device, said media access unit including circuitry to drive said second display device to indicate acceptable link status when there is a computing device coupled to said second jack which is transmitting link pulses to said testing device, said media access unit including circuitry to receive data packets from a network hub connected to said first jack, and said media access unit including circuitry to drive said third display device to indicate data packet reception when data packets are received from said network hub, and said media access unit including circuitry to receive data packets from a a computing device coupled to said second jack, and said media access unit including circuitry to drive said third display device to indicate data packet reception when data packets are received from said computing device coupled to said second jack, and wherein any said network hub coupled to said first jack is coupled by a cable which includes at least two conductors on which said network hub transmits link pulses, said media access unit being coupled to conductors of said cable coupling said first jack to said network hub and on which said network hub transmits link pulses and wherein said media access unit is coupled to said fourth display device such that if a positive going link pulse is detected on a predetermined one of said conductors on which said network hub transmits link pulses, said fourth display device is driven by circuitry in said media access unit to indicate correct polarity, and wherein any said computing device coupled to said second jack is coupled by a cable which includes at least two conductors on which said computing device transmits link pulses, said media access unit being coupled to said conductors of said cable on which said computing device transmits link pulses and wherein said media access unit is coupled to said fourth display device such that if a positive going link pulse is detected on a predetermined one of said conductors on which said computing device transmits link pulses, said fourth display device is driven by circuitry in said media access unit so as to indicate correct polarity.   
     
     
       3. A method for testing network connections to network interface circuits of personal computers, workstations, and other peripherals, hereafter referred to as computing devices, comprising the steps of: connecting the network interface circuit of a computing device to a portable testing device;   generating a link pulse in said portable testing device and coupling said link pulse to said network interface circuit of said computing device;   sensing whether said network interface circuit of said computing device generates a link pulse in response to said link pulse generated by said portable testing device;   if said network interface circuit of said computing device generates a link pulse in response to said link pulse generated by said portable testing device, driving a first display device to indicate acceptable link status;   sensing whether said link pulse transmitted by said network interface circuit of said computing device in response to said link pulse generated by said portable testing device has a predetermined polarity, and, if so, driving a second display device to indicate said predetermined polarity has been sensed for the connection between the portable testing device and said network interface circuit of said computing device; and   sensing whether said network interface circuit of said computing device transmits a data packet in response to said link pulse generated by said portable testing device, and, if so, driving a third display device to indicate a data packet is being received.   
     
     
       4. A method for testing network connections to repeaters coupled to ports of network hubs, comprising the steps of: connecting a repeater of a network hub to a portable testing device;   generating a link pulse in said portable testing device and coupling said link pulse to said repeater of said network hub;   sensing whether said repeater of said network hub generates a link pulse in response to said link pulse generated by said portable testing device;   if said repeater of said network hub generates and transmits to said portable testing device a link pulse in response to said link pulse generated by said portable testing device, driving a first display device to indicate acceptable link status;   sensing whether said link pulse generated and transmitted to said portable testing device by said repeater of said network hub has a predetermined polarity, and, if so, driving a second display device to indicate said predetermined polarity has been sensed; and   sensing whether said repeater of said network hub transmits a data packet in response to said link pulse generated by said portable testing device and coupled to said repeater of said network hub, and, if so, driving a third display device to indicate a data packet is being received.